One Construct or Many? Clarifying the Structure and Meaning of Measures of Psychological and Cognitive Flexibility and Their Components in a Community and Chronic Pain Sample

There are a plethora of "flexibility" constructs and measures in psychology, but the extent to which they assess the same or different constructs, and whether flexibility and inflexibility are separate constructs (vs. extremes of the same bipolar continuum), remains underexplored. We examined the distinctiveness of seven different self-report measures of psychological (in)flexibility and cognitive flexibility using an online community (<i>N</i> = 465) and a chronic pain sample (<i>N</i> = 445). We analyzed the latent structure of these questionnaires using item-level exploratory structural equation modeling that controlled for measure-specific variance, and we tested these factors in relation to a range of mental health outcomes (concurrent validity) and discriminant validity measures. Findings indicate that psychological and cognitive flexibility questionnaires can be characterized at multiple levels, including six lower-order components that span individual measures and global factors that account for their shared variance. The six factors were broadly and uniquely associated with clinically relevant variables, including symptoms and well-being. We also found support for the notion that flexibility and inflexibility exist on a single bipolar continuum, rather than being characterized as separate. Implications for clinical assessment in research and intervention settings are discussed.